# VehicleLocalPosition (UORB message)

Fused local position in NED. The coordinate system origin is the vehicle position at the time when the EKF2-module was started.

[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/VehicleLocalPosition.msg)

```c
# Fused local position in NED.
# The coordinate system origin is the vehicle position at the time when the EKF2-module was started.

uint64 timestamp            # time since system start (microseconds)
uint64 timestamp_sample                 # the timestamp of the raw data (microseconds)

bool xy_valid               # true if x and y are valid
bool z_valid                # true if z is valid
bool v_xy_valid             # true if vx and vy are valid
bool v_z_valid              # true if vz is valid

# Position in local NED frame
float32 x               # North position in NED earth-fixed frame, (metres)
float32 y               # East position in NED earth-fixed frame, (metres)
float32 z               # Down position (negative altitude) in NED earth-fixed frame, (metres)

# Position reset delta
float32[2] delta_xy
uint8 xy_reset_counter

float32 delta_z
uint8 z_reset_counter

# Velocity in NED frame
float32 vx              # North velocity in NED earth-fixed frame, (metres/sec)
float32 vy              # East velocity in NED earth-fixed frame, (metres/sec)
float32 vz              # Down velocity in NED earth-fixed frame, (metres/sec)
float32 z_deriv             # Down position time derivative in NED earth-fixed frame, (metres/sec)

# Velocity reset delta
float32[2] delta_vxy
uint8 vxy_reset_counter

float32 delta_vz
uint8 vz_reset_counter
# Acceleration in NED frame
float32 ax        # North velocity derivative in NED earth-fixed frame, (metres/sec^2)
float32 ay        # East velocity derivative in NED earth-fixed frame, (metres/sec^2)
float32 az        # Down velocity derivative in NED earth-fixed frame, (metres/sec^2)

float32 heading             # Euler yaw angle transforming the tangent plane relative to NED earth-fixed frame, -PI..+PI,  (radians)
float32 delta_heading
uint8 heading_reset_counter
bool heading_good_for_control

# Position of reference point (local NED frame origin) in global (GPS / WGS84) frame
bool xy_global              # true if position (x, y) has a valid global reference (ref_lat, ref_lon)
bool z_global               # true if z has a valid global reference (ref_alt)
uint64 ref_timestamp            # Time when reference position was set since system start, (microseconds)
float64 ref_lat             # Reference point latitude, (degrees)
float64 ref_lon             # Reference point longitude, (degrees)
float32 ref_alt             # Reference altitude AMSL, (metres)

# Distance to surface
float32 dist_bottom         # Distance from from bottom surface to ground, (metres)
bool dist_bottom_valid          # true if distance to bottom surface is valid
uint8 dist_bottom_sensor_bitfield   # bitfield indicating what type of sensor is used to estimate dist_bottom
uint8 DIST_BOTTOM_SENSOR_NONE = 0
uint8 DIST_BOTTOM_SENSOR_RANGE = 1  # (1 << 0) a range sensor is used to estimate dist_bottom field
uint8 DIST_BOTTOM_SENSOR_FLOW = 2   # (1 << 1) a flow sensor is used to estimate dist_bottom field (mostly fixed-wing use case)

float32 eph             # Standard deviation of horizontal position error, (metres)
float32 epv             # Standard deviation of vertical position error, (metres)
float32 evh             # Standard deviation of horizontal velocity error, (metres/sec)
float32 evv             # Standard deviation of vertical velocity error, (metres/sec)

bool dead_reckoning                     # True if this position is estimated through dead-reckoning

# estimator specified vehicle limits
float32 vxy_max             # maximum horizontal speed - set to 0 when limiting not required (meters/sec)
float32 vz_max              # maximum vertical speed - set to 0 when limiting not required (meters/sec)
float32 hagl_min            # minimum height above ground level - set to 0 when limiting not required (meters)
float32 hagl_max            # maximum height above ground level - set to 0 when limiting not required (meters)

# TOPICS vehicle_local_position vehicle_local_position_groundtruth external_ins_local_position
# TOPICS estimator_local_position

```
